Message Authentication Code (MAC), message authentication code

A specific ANSI standard for a checksum that is computed with a keyed hash that is based on DES. [A9009] Usage: a.k.a. Data Authentication Code, which is a U.S. Government standard. [FP113] (See: MAC.)

Synonym for "error detection code".

Deprecated Term: IDOCs SHOULD NOT use the uncapitalized form "message authentication code". Instead, use "checksum", "error detection code", "hash", "keyed hash", "Message Authentication Code", or "protected checksum", depending on what is meant. (See: authentication code.)

The uncapitalized form mixes concepts in a potentially misleading way. The word "message" is misleading because it implies that the mechanism is particularly suitable for or limited to electronic mail (see: Message Handling Systems). The word "authentication" is misleading because the mechanism primarily serves a data integrity function rather than an authentication function. The word "code" is misleading because it implies that either encoding or encryption is involved or that the term refers to computer software.